Patent GB-190802282-A (GB)
Title: Improvements in Apparatus for Imparting Variable Vibrating or Oscillating Motion to Printing Cylinders or Blocks in the Process of Engraving.
Inventor: DUNCAN JOHN PINKERTON
Filed: 1908-02-01
Granted: 1909-01-28
Abstract: 2282. Duncan, J. P. Feb. 1. Embossing.-Relates to mill engraving in which the different depth of design is obtained by the more or less frequent passage of the mill over the surface of the roller or block, and consists in providing automatic mechanical means for oscillating the roller in contact with the mill. A roller A is driven by spur-wheels A<3>, A<2> from a wheel A' on a shaft a carrying a bevelwheel C<3> gearing with wheels C<1>, C<2>, either of which may be clutched to the driving-shaft B<1> by a clutch C. The clutch C is operated by a fork c, a lever L<1> pivoted at l, and a connecting-rod L, from a bell-crank k, the slotted end K of which engages a pin i<2> in a rod i<1> attached to the carriage I. The carriage I is supported by rods i which slide in the stationary end frames d<x>. Resting in notches in the ends of the carriage I are a series (in this case two) of bars H each carrying two adjustable stops G, G' adapted to be engaged by a cross-head D' carried by a rack D reciprocated by gearing F<1>, F<2>, F<3>, a shaft E<2>, bevel-gearing E, E<1>, and a shaft D<2>, from . the shaft a. The bars H when in the operative position are supported on two segments M, each provided with a notch m into which one bar H is adapted to drop out of action at a point determined by stops O on a ratchet bar N<3> fed forward by a pawl N<2>, Figs. 2 and 4. The pawl N<2> is pivoted on an eccentric pin n<2> on a catch N pivoted on a bar secured to the stationary end frame d<x>. At each movement of the cross-head D<3> to the right, a catch I<1> engages the catch N and feeds the bar N' along until the first stop O engages a stop on the segment M and rocks it, so that the first bar H drops into the notch m out of action. When the second stop O engages the segment, it is further rocked, causing the second bar to fall out of action and-leaving the clutch mechanism to be controlled by stops G<2>, G<3> on the bar H<1> of the carriage I. A weighted cord or a helical spring attached to an eye N<4> in the ratchet bar N<3> tends to return the bar N<3>, but is normally prevented from doing so by a retaining-pawl N<5>. Both the pawls N<2>, N<5> are disengaged to return the bar N<3> by a projection q on a spring-held lever Q. The bars H are raised to the operative position again by pins R projecting laterally from two bars R', vertically movable by means of two bell-cranks and a longitudinally sliding rod S<1> operated by suitable means, shown in Fig. 1. In order to stop the apparatus, preferably in the mid-stroke of the cross-head D', an adjustable stop P, Fig. 2, secured to the bar N<3> engages a projection P' on a lever P<2>, pivoted to a stud p on the carriage I. The lever P<2> is thus lifted and the end p<1> of the projection P' intercepts the cross-head D<3> when the crosshead is moving towards the left, whereby the lever P<2> is carried along until its end p<3> abuts against the stop p<4>, taking with it the carriage I. In this position the rod i<1> moves the clutch C into mid-position, thus stopping the apparatus. In order to permit movement of the cylinder A without disturbing the controlling- mechanism, the bevel-gear E<1> is connected to its shaft E<2> by a clutch E<x>.